Helical multilevel cutting tool

ABSTRACT

A helical multilevel cutting tool has high heat emission efficiency, great strength and excellent durability, and can be positioned easily during drilling operation. The cutting tool includes a cutter shank and a cutter head which are integrally formed, wherein the cutter head is provided with several helical pieces integrally, each helical piece has a cutting blade thereon, a heat emission platform is formed along the cutting blade, a second cutting blade which faces forwardly as viewed in the direction of the cutting operation is formed in front of the heat emission platform, and a cutting blade outer surface is formed between the heat emission platform front surface and the second cutting blade. An outer front cutting blade is formed on the top surface of the cutter head at a position where the blade meets the heat emission platform front surface, and a front cutting blade is formed between the second cutting blade and the center of the cutter head top surface.

TECHNICAL FIELD

This invention relates to a helical multilevel cutting tool which isused in machining operations of a drilling machine, a milling machine, aboring machine, and etc.

BACKGROUND ART

At present, a twist drill used in machining operations comprises alateral edge, a cutting blade, and a helical sub-edge platform, and asub-edge substantially exhibits a single convex shape. Though a millingcutter has a structure in which its sub-edge and cutting edge aredistributively set as three edges, four edges, five edges, etc., thereis no great difference between its sub-edge and cutting edge and thoseof the twist drill. Such twist drill and milling cutter, when drilling(milling) work pieces of relatively high hardness, are liable togenerate a large amount of heat, cause the hardness of the cutter headsto be low, and result in the wear of the cutter heads, and at same timesuch cutter heads have a defect that they are liable to be broken.Further, since the cutting edges on both sides of the cutter head aresymmetrical in operation, and generally the cutting amount ranges onlyfrom about dozens of micrometers to 1 mm, the height of the repairingand grinding angle is difficult to be grasped when being repaired andground. In addition, in those twist drills and milling cutters, sincethe center position of the cutter head can not be easily grasped, theproblems are liable to be caused that the location is not accurate, thatthe precision of the machined hole is not qualified, that waste productsis easily resulted, and at the same time a thinner work piece, whenbeing machined, can be raised up to cause injury and accidents.

SUMMARY OF THE INVENTION

In view of the problems described above the present invention is madefor the purpose of providing a new type of helical multilevel cuttingtool, which has high heat emission efficiency, great strength andexcellent durability, and can be positioned easily during drillingoperation.

In order to achieve the above object, the present invention employsfollowing technical solution:

A helical multilevel cutting tool comprises a cutter shank and a cutterhead which are integrally formed, characterized by that: the cutter headis provided with several helical pieces integrally, each helical piecehas a cutting blade thereon, a heat emission platform is formed alongthe cutting blade, a second cutting blade which faces forwardly asviewed in the direction of the cutting operation is formed in front ofthe heat emission platform, a cutting blade outer surface is formedbetween the heat emission platform front surface and the second cuttingblade, an outer front cutting blade is formed on the top surface of thecutter head at a position where the blade meets the heat emissionplatform front surface, and a front cutting blade is formed between thesecond cutting blade and the center of the cutter head top surface.

Preferably, there is formed a helical positioning platform protrudingfrom the position of the cutter axis to the second cutting blade on thefront cutting surface of each helical piece.

Preferably, there is formed a groove on said helical positioningplatform.

Preferably, there is formed at least one level of helical multilevelblade between the second cutting blade and the side surface of saidhelical positioning platform.

Preferably, a concave helical multilevel blade is included in saidhelical multilevel blade.

Preferably, the length of said outer front cutting blade is equal to orless than a half of the radius from the outer side surface of the heatemission platform to the cutter axis.

Preferably, the perpendicular distance of the side surface of saidhelical positioning platform with respect to the cutter axis is equal toor less than a half of the radius from the outer side surface of theheat emission platform to the cutter axis.

Preferably, the angle included between the front surface of said heatemission platform and the cutting blade outer surface at their joint isat least 90°.

Preferably, said helical pieces are at least two.

Preferably, the cutter shank is one of the following types: a coneshank, a straight shank, a cylinder positioned screw shank, a cylinderpositioned thread-hole shank, a cone positioned screw shank, a conepositioned thread-hole shank, an end-surface platform positioned screwshank, and an end-surface platform positioned thread-hole shank.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution and advantages of the present invention will beillustrated in detail in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic view of a cutting tool of the first embodiment ofthe invention.

FIG. 2 is a schematic view of a cutting tool of the second embodiment ofthe invention.

FIG. 3 is a schematic view of a cutting tool of the third embodiment ofthe invention.

FIG. 4 is a schematic view of a cutting tool of the fourth embodiment ofthe invention.

FIG. 5 is a schematic view of a cutting tool having three helicalpieces.

FIG. 6 shows schematic views of various cutter shanks, wherein (A)represents a cone shank, (B) a straight shank, (C) a cylinder positionedscrew shank, (D) a cylinder positioned thread-hole shank, (E) a conepositioned screw shank, (F) a cone positioned thread-hole shank, (G) anend-surface platform positioned screw shank, and (H) an end-surfaceplatform positioned thread-hole shank.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiments of a helical multilevel cutting tool of thepresent invention will be illustrated below in detail in conjunctionwith the accompanying drawings, and in the first to fourth embodimentsthe cutting tool having two helical pieces is mainly illustrated asexamples.

First Embodiment

As shown in FIG. 1, a helical multilevel cutting tool of the firstembodiment of the invention comprises a cutter shank 1 and a cutter head2 which are integrally formed, the cutter head 2 is provided withseveral helical pieces 3 . . . 3 integrally, each helical piece 3 has acutting blade 4 thereon, a heat emission platform 5 is formed along thecutting blade 4, a second cutting blade 6 which faces forwardly asviewed in the direction of the cutting operation is formed in front ofthe heat emission platform 5, a cutting blade outer surface 7 is formedbetween the front surface 5 a of the heat emission platform 5 and thesecond cutting blade 6, an outer front cutting blade 9 is formed on thetop surface 8 of the cutter head 2 at a position where the top surface 8meets the front surface 5 a of the heat emission platform 5, and a frontcutting blade 10 is formed on the position between the second cuttingblade 6 and the center of the top surface 8. In addition, the length ofsaid outer front cutting blade 9 is equal to or less than a half of theradius from the outer side surface 5 b of the heat emission platform 5to the cutter axis, and the angle included between the front surface 5 aof said heat emission platform 5 and the cutting blade outer surface 7at their joint is at least 90° and may also be transitioned by an arc.

According to the structure described above, since on each helical piece3 there is formed the heat emission platform 5 along the cutting blade4, and the second cutting blade 6 which faces forwardly as viewed in thedirection of the cutting operation is formed in front of the heatemission platform 5, there is added one new second cutting blade 6 incomparison with the conventional cutter head, so that the two cuttingblades can perform operation, thereby capable of resolving the cuttingforce of the cutting blade, lowing the friction strength of the cuttingblade, causing the heat generated by friction to be reduced, at the sametime also increasing the heat emission area of the cutter head, lowingthe temperature of the cutter head, extending the use life of thecutter, and always remaining high strength in the machining process.

As shown in FIG. 6(A)-FIG. 6(H), the cutter shank 1 may be formed intovarious structures according to machining requirements, for example,when being applied to a drilling machine to perform drilling operation,may be a common cone shank (A) or a straight shank (B); and when beingapplied to a milling machine to perform milling operation, may be acylinder positioned screw shank (C), a cylinder positioned thread-holeshank (D), a cone positioned screw shank (E), a cone positionedthread-hole shank (F), an end-surface platform positioned screw shank(G), an end-surface platform positioned thread-hole shank (H) and etc.

By making the cutter shank have the structures described above, thecutting tool of the invention can widen its application scope and can beused in many machining operations.

Second Embodiment

As shown in FIG. 2, a helical multilevel cutting tool of the secondembodiment of the invention, based on the structure of the firstembodiment, is formed with a helical positioning platform 12 protrudingfrom the position of the cutter axis to the second cutting blade 6 onthe front cutting surface 11 of each helical piece 3. In the secondembodiment, the perpendicular distance of the side surface 12 a of saidhelical positioning platform 12 with respect to the cutter axis is equalto or less than a half of the radius from the outer side surface 5 b ofthe heat emission platform 5 to the cutter axis. When the drillingcutter is relatively small, such as φ4 mm, the second cutting blade 6and the positioning platform cutting blade 16 coincide into one integralbody.

By such configuration, on the base of technical effects of the firstembodiment, since the protruding helical positioning platform 12 isformed on the front cutting surface 11 of each helical piece 3, there isformed a positioning center comparison with the prior conventionalcutter head, so that the better positioning can be performed duringmachining operations to further improve the machining precision, and theproblem can be prevented that a thinner work piece, when being drilled,can be raised up due to the unstable positioning.

The cutter shank of this embodiment can employ the same structure asthat of the first embodiment, and therefore its illustration is omittedhere.

Third Embodiment

As shown in FIG. 3, a helical multilevel cutting tool of the thirdembodiment of the invention, based on the structure of the secondembodiment, is formed with a groove 13 on said helical positioningplatform 12.

By such configuration, on the base of technical effects of the secondembodiment, since the groove 13 is formed on said helical positioningplatform 12, the positioning can be further enhanced, and at same timethe heat emission efficiency is improved because of the increase of theheat emission area.

The cutter shank of this embodiment can employ the same structure asthat of the first embodiment, and therefore its illustration is omittedhere.

Fourth Embodiment

As shown in FIG. 4, a helical multilevel cutting tool of the fourthembodiment of the invention, based on the structure of the secondembodiment, is formed with a three-level helical blade 14 between thesecond cutting blade 6 and the side surface 12 a of said helicalpositioning platform 12, in the three-level helical blade 14, atwo-level concave helical blade 15 is included.

By such configuration, on the base of technical effects of the secondembodiment, since there is formed the three-level helical blade 14including the two-level concave helical blade 15, the cutting force ofthe front cutting blade 10 can be further resolved and reduced, therebyreducing the amount of the heat emission, at the same time being capableof further increasing the heat emission area of the cutter head, lowingthe temperature of the cutter head, extending the use life the cuttingtool, and always remaining high strength in the drilling operation toimprove operation efficiency.

The cutter shank of this embodiment can employ the same structure asthat of the first embodiment, and therefore its illustration is omittedhere.

Although the cutting tool having two helical pieces is illustrated asexamples, the cutting tool of the invention may also have more helicalpieces, and various helical pieces can employ the structures of theembodiments described above and the combination of any other manners.FIG. 5 shows a cutting tool having three helical pieces 3, the structureof each of which is the same as that of the fourth embodiment.

The preferred embodiments described above is illustrative rather thanlimiting, and the invention can also be embodied and practiced in othermanners without departing from the main point and basic features of theinvention. The scope of the invention is defined by claims, and allalternations within the scope defined by claims fall in the scope of theinvention.

1. A helical multilevel cutting tool, comprising a cutter shank and acutter head which are integrally formed, characterized by that: thecutter head is provided with a plurality of helical pieces integrally,each helical piece has a cutting blade thereon, a heat emission platformis formed along the cutting blade, a second cutting blade which facesforwardly as viewed in the direction of the cutting operation is formedin front of the heat emission platform, a cutting blade outer surface isformed between the heat emission platform front surface and the secondcutting blade, an outer front cutting blade is formed on the top surfaceof the cutter head at a position where the blade meets the heat emissionplatform front surface, and a front cutting blade is formed between thesecond cutting blade and the center of the cutter head top surface. 2.The helical multilevel cutting tool according to claim 1, characterizedby that, there is formed a helical positioning platform protruding fromthe position of the cutter axis to the second cutting blade on the frontcutting surface of each helical piece.
 3. The helical multilevel cuttingtool according to claim 2, characterized by that, there is formed agroove on said helical positioning platform.
 4. The helical multilevelcutting tool according to claim 2 or 3, characterized by that, there isformed at least one level of helical multilevel blade between the secondcutting blade and the side surface of said helical positioning platform.5. The helical multilevel cutting tool according to claim 4,characterized by that, a concave helical multilevel blade is included insaid helical multilevel blade.
 6. The helical multilevel cutting toolaccording to any of claims 1-5, characterized by that, the length ofsaid outer front cutting blade is equal to or less than a half of theradius from the outer side surface of the heat emission platform to thecutter axis.
 7. The helical multilevel cutting tool according to any ofclaims 2-6, characterized by that, the perpendicular distance of theside surface of said helical positioning platform with respect to thecutter axis is equal to or less than a half of the radius from the outerside surface of the heat emission platform to the cutter axis.
 8. Thehelical multilevel cutting tool according to any of claims 1-7,characterized by that, the angle included between the front surface ofsaid heat emission platform and the cutting blade outer surface at theirjoint is at least 90°.
 9. The helical multilevel cutting tool accordingto any of claims 1-8, characterized by that, said helical pieces are atleast two.
 10. The helical multilevel cutting tool according to any ofclaims 1-9, characterized by that, the cutter shank is one of thefollowing types: a cone shank, a straight shank, a cylinder positionedscrew shank, a cylinder positioned thread-hole shank, a cone positionedscrew shank, a cone positioned thread-hole shank, an end-surfaceplatform positioned screw shank, and an end-surface platform positionedthread-hole shank.